Manufacturing method

Abstract

To provide a manufacturing method capable of restraining fragments from dropping during grinding.SOLUTION: A manufacturing method for manufacturing a plurality of chips by dividing a workpiece with a plurality of intersecting scheduled division lines set thereon includes: a cutting step 101 of cutting a front surface of the workpiece by a cutting blade to form cut grooves along the scheduled division lines; and a grinding step 102 of grinding a rear surface as a back surface of the front surface of the workpiece to thereby thin the workpiece to a finish thickness of reaching the cut grooves and to divide the workpiece into the plurality of chips after performing the cutting step 101. The cut grooves are formed such that a position of a groove bottom in a thickness direction of the workpiece varies in a width direction of the cut groove. In the grinding step 102, the grinding is started from a tip of the groove bottom of the cut groove which is remote from the front surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a manufacturing method for manufacturing a plurality of chips by dividing a workpiece having a plurality of intersecting planned dividing lines. [Background technology]

[0002] As a method for thinning a semiconductor wafer and dividing it into individual device chips, a process called DBG (Dicing Before Grinding) has been proposed (see, for example, Patent Document 1).

[0003] In the DBG process, the front side of a wafer on which devices are formed is cut along a planned dividing line with a cutting blade, and a groove with a depth less than the thickness of the wafer is formed along the planned dividing line. After that, a surface protection member is placed on the front side of the wafer, and then the back side of the wafer is ground to expose the groove on the back side of the wafer and divide the wafer into multiple device chips. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-007653 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the method described in Patent Document 1, when the back side of the wafer is ground, the bottom of the cut groove becomes thin and may break during grinding, causing fragments to fall. If the fragments adhere to other devices during subsequent processes or handling, this can cause device defects, which is problematic.

[0006] An object of the present invention is to provide a manufacturing method capable of suppressing the falling of chips during grinding. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the manufacturing method of the present invention is a manufacturing method for dividing a workpiece having a plurality of intersecting planned division lines to produce a plurality of chips, and includes a cutting step in which one side of the workpiece is cut with a cutting blade to form a cutting groove along the planned division line, and after performing the cutting step, a grinding step in which the other side of the workpiece, which is the back side of the one side, is ground to thin the workpiece to a finishing thickness reaching the cutting groove, thereby dividing the workpiece into a plurality of chips, wherein the cutting groove is formed so that the position of the groove bottom in the thickness direction of the workpiece differs in the width direction of the cutting groove, and in the grinding step, grinding is performed from the tip of the groove bottom.

[0008] In the manufacturing method, in the cutting step, the depth of all of the groove bottoms of the cut grooves from the one surface may be formed to be deeper than the finished thickness from the one surface.

[0009] In the manufacturing method, in the cutting step, the cutting groove may be formed by a cutting blade whose blade thickness gradually decreases toward a tip.

[0010] In the manufacturing method, in the cutting step, the cutting grooves may be formed by cutting the intended division lines a plurality of times with a cutting blade while varying the cutting depth and cutting position. Effect of the Invention

[0011] The present invention has an effect of suppressing the falling of chips during grinding. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view that illustrates a workpiece to be processed in the manufacturing method according to the first embodiment. [Diagram 2] FIG. 2 is a flowchart showing the flow of the manufacturing method according to the first embodiment. [Diagram 3]FIG. 3 is a front view of a cutting unit used in the cutting step of the manufacturing method shown in FIG. [Figure 4] FIG. 4 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. [Diagram 5] FIG. 5 is a perspective view that illustrates a cutting step in the manufacturing method illustrated in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a main part of the workpiece after the cutting step of the manufacturing method shown in FIG. [Figure 7] FIG. 7 is a front view of a modification of the cutting unit shown in FIG. [Figure 8] FIG. 8 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. [Figure 9] FIG. 9 is a perspective view that typically illustrates a state in which a surface protection member is attached to the surface of a workpiece in the grinding step of the manufacturing method illustrated in FIG. [Figure 10] FIG. 10 is a cross-sectional view that typically shows a main part of a workpiece having a surface protection member attached to its surface in the grinding step of the manufacturing method shown in FIG. [Figure 11] FIG. 11 is a perspective view that typically shows the back surface of the workpiece being ground in the grinding step of the manufacturing method shown in FIG. [Figure 12] FIG. 12 is a perspective view that typically shows a main part of a workpiece in the middle of having its back surface ground in the grinding step of the manufacturing method shown in FIG. [Figure 13] FIG. 13 is a perspective view showing a schematic view of a main part of the workpiece after the grinding step of the manufacturing method shown in FIG. [Figure 14] FIG. 14 is a front view of a cutting unit used in the cutting step of the manufacturing method according to the second embodiment. [Figure 15] 15 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. [Figure 16] FIG. 16 is a cross-sectional view that illustrates a schematic view of a main part of a workpiece during a cutting step of a manufacturing method according to the second embodiment. [Figure 17]FIG. 17 is a front view of a modification of the cutting unit shown in FIG. [Figure 18] 18 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. [Figure 19] FIG. 19 is a cross-sectional view that typically shows a main part of a workpiece having a surface protection member attached to its surface in the grinding step of the manufacturing method according to the second embodiment. [Figure 20] FIG. 20 is a perspective view that typically shows a main part of a workpiece in the middle of having its back surface ground in the grinding step of the manufacturing method according to the second embodiment. [Figure 21] FIG. 21 is a perspective view that illustrates a main part of the workpiece after the grinding step of the manufacturing method according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0014] [Embodiment 1] A manufacturing method according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing a typical example of a workpiece to be processed by the manufacturing method according to the first embodiment. Fig. 2 is a flow chart showing the flow of the manufacturing method according to the first embodiment.

[0015] (workpiece) The manufacturing method according to the embodiment is a method for processing a workpiece 1 shown in Fig. 1. The workpiece 1 to be processed in the manufacturing method according to the embodiment is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer, with a substrate 2 made of silicon (Si), gallium arsenide (GaAs), silicon carbide (SiC), sapphire, or the like.

[0016] A plurality of dividing lines 4 intersecting the surface 3 (corresponding to one surface) are set on the workpiece 1, and devices 5 are formed in each of the areas partitioned by the dividing lines 4 on the surface 3. The devices 5 are, for example, integrated circuits such as ICs (Integrated Circuits) or LSIs (Large Scale Integration), image sensors such as CCDs (Charge Coupled Devices) or CMOSs ​​(Complementary Metal Oxide Semiconductors), optical elements such as LEDs (Light-Emitting Diodes), MEMS (Micro Electro Mechanical Systems), or semiconductor memories (semiconductor memory devices).

[0017] The workpiece 1 is thinned to a finish thickness 6 and divided into individual chips 10 along the intended division lines 4. Each chip 10 includes a part of the substrate 2 and a device 5.

[0018] In the first embodiment, a TEG (Test Element Group) (not shown) is formed on the surface 3 of the planned division lines 4. The TEG is made of a conductive metal and is an evaluation element for finding problems that may occur in the device 5 in terms of design or manufacturing.

[0019] In the present invention, the workpiece 1 does not have to have a device 5 formed thereon, and is not limited to a wafer such as a semiconductor wafer or an optical device wafer. For example, the workpiece 1 may be a rectangular package substrate having a plurality of devices sealed with resin, a ceramic plate, a glass plate, or the like.

[0020] (Manufacturing method) The manufacturing method according to the first embodiment is a method for manufacturing a plurality of chips 10 by dividing a workpiece 1, on which a plurality of planned division lines 4 are formed, along the planned division lines 4. As shown in FIG. 2, the manufacturing method according to the first embodiment includes a cutting step 101 and a grinding step 102.

[0021] (Cutting step) FIG. 3 is a front view of a cutting unit used in the cutting step of the manufacturing method shown in FIG. 2. FIG. 4 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. 3. FIG. 5 is a perspective view that typically shows the cutting step of the manufacturing method shown in FIG. 2. FIG. 6 is a cross-sectional view that shows a main part of a workpiece after the cutting step of the manufacturing method shown in FIG. 2. FIG. 7 is a front view of a modified example of the cutting unit shown in FIG. 3. FIG. 8 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. 7.

[0022] The cutting step 101 is a step of cutting the surface 3 of the workpiece 1 with a cutting blade 21 shown in Figures 3 and 4 to form a cutting groove 11 (shown in Figures 5 and 6) along the planned division line 4. In the first embodiment, the cutting blade 21 used in the cutting step 101 is attached to the tip of the spindle 23 of the cutting unit 22 of the cutting device 20, and is rotated around the axis of the spindle 23 to cut the workpiece 1.

[0023] In the first embodiment, the cutting blade 21 is an extremely thin cutting grindstone having a substantially ring shape. In the first embodiment, the cutting blade 21 is a so-called hablade that includes a circular annular base 24 and a circular cutting blade 25 that is disposed on the outer periphery of the circular base 24 and cuts the workpiece 1. The cutting blade 25 is made of abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a bond material such as metal or resin, and is formed to a predetermined thickness. In the present invention, the cutting blade 21 may be a so-called washer blade that does not include the circular base 24 and is made of only the circular cutting blade 25.

[0024] In the first embodiment, the cutting edge 26 of the cutting blade 25 of the cutting blade 21 is formed in a V-shape so that the outer diameter is largest at the center in the thickness direction and gradually decreases from the center in the thickness direction toward both surfaces. In the first embodiment, the cutting blade 21 is a so-called V-blade. In the first embodiment, the cutting edge 26 of the cutting blade 25 of the cutting blade 21 has two tip surfaces 271, 272 that intersect with each other and have a flat cross section, as shown in FIG. 4. The angle θ between the tip surfaces 271, 272 of the cutting edge 26 of the cutting blade 25 of the cutting blade 21 is 120° or more and 160° or less. In this way, in the cutting step 101, the cutting groove 11 is formed by the cutting blade 21 whose blade thickness gradually decreases toward the tip.

[0025] In the first embodiment, in the cutting step 101, the cutting device 20 suction-holds the back surface 7 (corresponding to the other surface) of the workpiece 1 on the holding surface of the chuck table, moves the chuck table toward the processing area, captures an image of the workpiece 1 with an imaging unit (not shown), and performs alignment to align the planned division lines 4 with the cutting edge 25 of the cutting blade 21. In the first embodiment, in the cutting step 101, the cutting device 20 relatively moves the workpiece 1 and the cutting unit 22 along the planned division lines 4 while supplying cutting water to the cutting blade 21 rotating around its axis, as shown in Fig. 5, and causes the cutting blade 21 to cut into each planned division line 4 in sequence to a cutting depth deeper than the finishing thickness 6, thereby forming cut grooves 11 along the planned division lines 4 of the workpiece 1.

[0026] In the cutting step 101 of the first embodiment, the cutting device 20 cuts the cutting blade 21 once into each of the division lines 4 from the surface 3 side of the workpiece 1 to a depth deeper than the finishing thickness 6. For this reason, in the cutting step 101 of the first embodiment, the cutting device 20 forms cut grooves 11 having V-shaped groove bottoms 12 in each of the division lines 4, as shown in Fig. 6. Thus, in the cutting step 101 of the first embodiment, the depth of all the groove bottoms 12 of the cut grooves 11 from the surface 3 is formed deeper than the finishing thickness 6 from the surface 3, and the cut grooves 11 are formed such that the position of the groove bottoms 12 in the thickness direction of the workpiece 1 differs in the width direction of the cut grooves 11.

[0027] In addition, in embodiment 1, in the present invention, the cutting blade 21-1 used in the cutting step 101 may be a so-called single V-blade, in which the tip surface 273 of the cutting edge 26 of the cutting edge 25 is formed by a single surface having a flat cross section inclined relative to the axis, as shown in Figures 7 and 8.

[0028] In the first embodiment, the cutting step 101 forms the cutting groove 11 having a width 13 of 50 μm or more and 150 μm or less. In the present invention, the width 13 of the cutting groove 11 is preferably a width that allows the TEG formed on the division lines 4 to be completely removed by cutting.

[0029] The cutting blade 21, 21-1 used in the cutting step 101 described above may be a blade with an R-shaped or tapered cutting edge 26 of the cutting blade 25, but in this case, since it is difficult to control the shape of the cutting edge 26 (it is difficult to shape it into a desired shape), it is preferable that the cutting blade 21, 21-1 used in the cutting step 101 is a V-blade as shown in Fig. 4 or a single V-blade as shown in Fig. 8. It is also preferable that the cutting blade 21, 21-1 is shaped into a V-shape or a single V-shape by checking the shape of the cutting edge 26 of the cutting blade 25 at a predetermined timing and dressing it.

[0030] When shaping the shape of the cutting edge 26 of the cutting blade 25, the cutting blade 25 is cut into the dress board to shape the cutting edge. Specifically, when shaping the shape of the cutting edge 26 of the cutting blade 25, the cutting blade 21, 21-1 cuts the cutting blade 25 into the dress board by the same operation as flat dressing (i.e., positioning the rotating cutting blade 21 at a predetermined cutting depth and moving it along the axis from a state where it is positioned on the outer periphery side of the dress board). Note that the cutting edge of the cutting blade 25 of the cutting blade 21, 21-1 is inclined in the thickness direction by adjusting the type of dress board used (the abrasive grain size and bonding material contained therein) and the Y movement speed. When forming a one-sided V shape, the cutting blade 21 is moved only in one direction in the axial direction to form a slope in half of the thickness direction, and when forming a V shape, the cutting blade 21 is moved only in one direction in the axial direction to form a slope in the remaining half of the thickness direction, and then moved in the other direction in the axial direction to form a slope in the remaining half of the thickness direction.

[0031] (Grinding step) Fig. 9 is a perspective view showing a state where a surface protection member is attached to the surface of a workpiece in the grinding step of the manufacturing method shown in Fig. 2. Fig. 10 is a cross-sectional view showing a main part of a workpiece having a surface protection member attached to the surface in the grinding step of the manufacturing method shown in Fig. 2. Fig. 11 is a perspective view showing a main part of a workpiece in the middle of grinding a back surface of the workpiece in the grinding step of the manufacturing method shown in Fig. 2. Fig. 12 is a perspective view showing a main part of a workpiece in the middle of grinding a back surface of the workpiece in the grinding step of the manufacturing method shown in Fig. 2. Fig. 13 is a perspective view showing a main part of a workpiece after the grinding step of the manufacturing method shown in Fig. 2.

[0032] In the grinding step 102, after the cutting step 101 is performed, the back surface 7 of the workpiece 1, which is the other surface behind the front surface 3, is ground to thin the workpiece 1 to a finishing thickness 6 leading to the cut grooves 11, thereby dividing the workpiece 1 into a plurality of chips 10. In the first embodiment, in the grinding step 102, a surface protection member 14 shown in Figs. 9 and 10 is attached to the front surface 3 of the workpiece 1.

[0033] In the first embodiment, the surface protection member 14 is an adhesive tape including a base material made of a flexible, non-adhesive resin and a glue layer made of a flexible, adhesive resin laminated on the base material. In the present invention, the surface protection member 14 may be a glueless tape that does not have a glue layer and is made of only a base material made of a non-adhesive thermoplastic resin and is thermocompressed to the workpiece 1, or may be a hard plate formed into a disk shape from a hard resin.

[0034] In the first embodiment, in the grinding step 102, the grinding device 30 sucks and holds the front surface 3 side of the workpiece 1 on the holding surface 32 of the chuck table 31 via the surface protection member 14. In the first embodiment, in the grinding step 102, as shown in Fig. 11, the grinding device 30 rotates the grinding wheel 34 for grinding about its axis by the spindle 33 and rotates the chuck table 31 about its axis, and while supplying grinding water from a grinding water nozzle (not shown), the grinding stone 35 of the grinding wheel 34 is brought into contact with the back surface 7 of the workpiece 1 and moved toward the chuck table 31 at a predetermined feed rate, and the back surface 7 side of the workpiece 1 is ground with the grinding stone 35.

[0035] In the first embodiment, as shown in FIG. 12, in the grinding step 102, the grinding device 30 grinds the workpiece 1 from the tip of the groove bottom 12 of the cut groove 11 away from the surface 3. In the first embodiment, as shown in FIG. 13, in the grinding step 102, when the thickness of the workpiece 1 reaches the finishing thickness 6, the grinding device 30 moves the grinding wheel 34 away from the back surface 7 of the workpiece 1, and ends the grinding step 102. Then, the cut groove 11 is exposed on the back surface 7 side of the workpiece 1, and the workpiece 1 is divided into individual chips 10. Thus, in the first embodiment, in the grinding step 102, the workpiece 1 is ground from the tip of the groove bottom 12 of the cut groove 11.

[0036] In the manufacturing method according to the first embodiment described above, in the cutting step 101, the cut groove 11 is formed so that the depth of the groove bottom 12 of the cut groove 11 from the surface 3 varies in the width direction. For this reason, in the manufacturing method according to the first embodiment, the cut groove 11 is gradually ground from the tip of the groove bottom 12 on the side away from the surface 3 in the grinding step 102, so that debris is less likely to fall into the cut groove 11.

[0037] As a result, the manufacturing method according to the first embodiment has the advantage of being able to suppress the falling of chips during grinding.

[0038] [Embodiment 2] The manufacturing method according to the second embodiment will be described with reference to the drawings. FIG. 14 is a front view of a cutting unit used in the cutting step of the manufacturing method according to the second embodiment. FIG. 15 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. 14. FIG. 16 is a cross-sectional view showing a main part of the workpiece during the cutting step of the manufacturing method according to the second embodiment. FIG. 17 is a front view of a modified example of the cutting unit shown in FIG. 14. FIG. 18 is a front view of the cutting edge of the cutting blade of the cutting unit shown in FIG. 17. FIG. 19 is a cross-sectional view showing a main part of the workpiece having a surface protection member attached to its front surface in the grinding step of the manufacturing method according to the second embodiment. FIG. 20 is a perspective view showing a main part of the workpiece in the middle of grinding the back surface in the grinding step of the manufacturing method according to the second embodiment. FIG. 21 is a perspective view showing a main part of the workpiece after the grinding step of the manufacturing method according to the second embodiment. 14, 15, 16, 17, 18, 19, 20, and 21, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

[0039] In the second embodiment, the cutting blade 21-2 used in the cutting step 101 has a tip surface 274 of the cutting edge 26 of the cutting blade 25 formed flat along the axis as shown in Figs. 14 and 15. In the second embodiment, in the cutting step 101, the cutting device 20 causes the cutting blade 21-2 to cut into each of the division lines 4 of the workpiece 1 multiple times with the cutting depth differing by at least one degree so that the cut grooves are parallel to each other and connected to each other. Thus, in the second embodiment, in the cutting step 101, the cutting device 20 cuts into each of the division lines 4 multiple times with the cutting blade 21-2 with different cutting depths and cutting positions as shown in Fig. 16, to form a single cut groove 11 with a step formed at the groove bottom 12 on each of the division lines 4.

[0040] 16, the cutting blade 21-2 is caused to cut into each of the division lines 4 three times at different positions in the width direction, and the cutting depth of the cutting blade 21-2 is set to the same at both ends of the division lines 4 in the width direction indicated by the dashed line and the two-dot chain line, and the cutting depth of the cutting blade 21-2 is set to be deeper at the center of the division lines 4 in the width direction indicated by the solid line than the cutting depth at both ends. Note that, in the second embodiment as well, the cutting depth of the cutting blade 21-2 is deeper than the finishing thickness 6.

[0041] Thus, in the cutting step 101 of the manufacturing method of embodiment 2, the depth of all groove bottoms 12 of the cut grooves 11 from the surface 3 is formed deeper than the finishing thickness 6 from the surface 3, and the cut grooves 11 are formed so that a step is formed at the groove bottoms 12 in the thickness direction of the workpiece 1, and the position of the groove bottoms 12 varies in the width direction of the cut grooves 11.

[0042] In the present invention, in the second embodiment, the cutting blade 21-3 used in the cutting step 101 may have a tip surface 275 of the cutting edge 26 of the cutting blade 25 formed in an arc-shaped cross section as shown in Fig. 17 and Fig. 18. In the present invention, in the second embodiment, the present invention is not limited to a form in which one cut groove 11 is formed by three cuts for each planned division line 4, but it is sufficient to form the cut groove 11 by a plurality of cuts, and is not limited to a form in which the cut groove 11 is deepest at the center in the width direction, but may be cut so that it becomes deeper from one side to the other in the width direction of the groove.

[0043] In the grinding step 102 of the manufacturing method according to the second embodiment, as in the first embodiment, as shown in FIG. 19, a surface protection member 14 is attached to the surface 3 of the workpiece 1. In the grinding step 102 of the manufacturing method according to the second embodiment, as in the first embodiment, as shown in FIG. 20, the back surface 7 of the workpiece 1 is ground, and the workpiece 1 is ground from the tip of the groove bottom 12 of the cut groove 11 away from the surface 3. In the grinding step 102 of the manufacturing method according to the second embodiment, as in the first embodiment, as shown in FIG. 21, when the thickness of the workpiece 1 reaches the finishing thickness 6, the grinding device 30 moves the grinding wheel 34 away from the back surface 7 of the workpiece 1, and the grinding step 102 is terminated. Then, the cut groove 11 is exposed on the back surface 7 side of the workpiece 1, and the workpiece 1 is divided into individual chips 10. Thus, in the first embodiment, in the grinding step 102, the workpiece 1 is ground from the tip of the groove bottom of the cut groove 11.

[0044] In the manufacturing method of embodiment 2, in the cutting step 101, the cut groove 11 is formed so that the depth of the groove bottom 12 of the cut groove 11 from the surface 3 varies in the width direction, and in the grinding step 102, the cut groove 11 is gradually ground from the tip on the side away from the surface 3 of the groove bottom 12, thereby achieving the effect of suppressing the falling of fragments during grinding, similar to embodiment 1.

[0045] Next, the inventor of the present invention confirmed the effect of the manufacturing method according to the embodiment 1. In the confirmation, the falling state of the broken pieces of the grinding step 102 when the cutting groove 11 was formed by the cutting blade 21 having different angles θ was confirmed. The results are shown in Table 1 below.

[0046] In Comparative Example 1, the angle θ was 180 degrees, i.e., the cutting blade 21-2 shown in Fig. 15 was used to cut each division line 4 only once to form the cut grooves 11. In Comparative Example 2, the cutting blade 21 was used to cut each division line 4 only once to form the cut grooves 11. In Comparative Example 3, the cutting blade 21 was used to cut each division line 4 only once to form the cut grooves 11.

[0047] [Table 1]

[0048] In the present invention 1, the cutting blade 21 with an angle θ of 160 degrees was used to cut each division line 4 only once to form the cut groove 11. In the present invention 2, the cutting blade 21 with an angle θ of 150 degrees was used to cut each division line 4 only once to form the cut groove 11. In the present invention 3, the cutting blade 21 with an angle θ of 140 degrees was used to cut each division line 4 only once to form the cut groove 11. In the present invention 4, the cutting blade 21 with an angle θ of 130 degrees was used to cut each division line 4 only once to form the cut groove 11. In the present invention 5, the cutting blade 21 with an angle θ of 120 degrees was used to cut each division line 4 only once to form the cut groove 11.

[0049] According to Table 1, in Comparative Example 1 and Comparative Example 2, pieces fell during the grinding step 102. In Comparative Example 3, pieces did not fall during the grinding step 102, but the cutting depth of the cutting blade 21 increased, which was not preferable as it prolonged the processing time for forming the cutting groove 11.

[0050] In contrast to Comparative Examples 1, 2, and 3, in the present invention products 1, 2, 3, 4, and 5, no debris fell during the grinding step 102, and the processing time for forming the cutting groove 11 was not prolonged.

[0051] According to Table 1, it is clear that by forming the cutting groove 11 with a cutting blade 21 having an angle θ of 120 degrees or more and 160 degrees or less, preferably an angle θ of 120 degrees or more and 130 degrees or less, no debris falls during the grinding step 102 and the processing time for forming the cutting groove 11 is not prolonged.

[0052] It should be noted that the present invention is not limited to the above-described embodiment, etc. In other words, the present invention can be practiced in various modified forms without departing from the gist of the present invention. [Explanation of symbols]

[0053] 1 Workpiece 3 Surface (one side) 4. Planned division line 6 Finishing thickness 7 Back side (other side) 10 Chips 11 Cutting groove 12 Groove bottom 21, 21-1, 21-2, 21-3 Cutting blade 101 Cutting Step 102 Grinding Step

Claims

1. A manufacturing method for manufacturing a plurality of chips by dividing a workpiece having a plurality of intersecting division lines, the method comprising the steps of: a cutting step of cutting one surface of the workpiece with a cutting blade to form a cutting groove along the intended division line; and a grinding step of grinding the other surface of the workpiece, which is the back surface of the one surface, after the cutting step is performed, to thin the workpiece to a finishing thickness reaching the cut grooves and divide the workpiece into a plurality of chips, The cut groove is formed such that the position of the groove bottom in the thickness direction of the workpiece varies in the width direction of the cut groove; In the grinding step, grinding is performed from the tip of the groove bottom.

2. 2. The manufacturing method according to claim 1, wherein in the cutting step, the depth of all of the groove bottoms from the one surface is formed deeper than the finished thickness from the one surface.

3. The manufacturing method according to claim 1 or 2, wherein in the cutting step, the cutting groove is formed by a cutting blade whose cutting thickness gradually decreases toward a tip.

4. 3. The manufacturing method according to claim 1, wherein in the cutting step, the cutting grooves are formed by cutting the respective intended division lines a plurality of times with a cutting blade with different cutting depths and positions.

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